Using streamline passenger cars on 18R curve


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burakol

Member
Hi -

I just wanted to ask if it is hopeless for us to use our old Athearn and Con-Cor streamline passenger cars if we are using 18R curves in our club layout? Some of my students are looking forward in running them in our layout but we always encounter issues with derailment... The cars still uses the truck mounted hook couplers and plastic wheels... is it even worth changing over to knuckle coupler and will it make a difference knowing that we are only limited in using an 18r curve?

Thanks!
 
burakol said:
I just wanted to ask if it is hopeless for us to use our old Athearn and Con-Cor streamline passenger cars if we are using 18R curves in our club layout? Some of my students are looking forward in running them in our layout but we always encounter issues with derailment... The cars still uses the truck mounted hook couplers and plastic wheels...
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In this case having the truck mounted couplers is a good thing. That is what will allow them to negotiate those tight curves. So, no it is certainly not hopeless they were designed for 18" curves. To solve the derailment issues I would first look for two things kinks in the track and improper wheel gauges. If those check out then start looking at how tight the truck are mounted - do they pivot easily and have just a bit of sided to side and front to back rock to them.

is it even worth changing over to knuckle coupler and will it make a difference knowing that we are only limited in using an 18r curve?
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I say no. If you are having derailment problems changing the couplers will probably not help. If they are drooping down they could be catching on other parts of the trackwork and causing the derailment. If they are not pivoting in their mounts I suppose that could also contribute to derailments. Either of those could be fixed without converting, but I still say trucks and track are the first and most likely cause.
 
I think you mentioned that they were 72' cars. They should be fine especially if the couplers are truck mounted, as far as negotiating the radius. Check your track for dips and peaks, or spreading i.e. the ends of the tracks bend in or out at the joins. Also bent, twisted joiners.
 
Wobbling track causes the bodies above them to wobble, except that sometimes the tops of the truck frames make contact with the underside of the frame on curves and this causes the wheels to jump out of the gauge. Or maybe some flashing on a bearing surface, even near it, needs to be removed.

When I have performance problems related to railing, I get a lot of light and I prepare to make a bunch of repeated passes over the affected area in slow order. I get my nose onto the table so that my eyes can see what is happening. I'll even wear my Opti-Visor. Eventually I notice something that gives me and idea of what to work on. Often it is a slight rise in the outer rail on a curve. On longer frames, that often causes the leading truck to lift out of the gauge if it happens to be at a dip in the rail.

Those cars aren't especially long, and with truck-mounted couplers they should not be having derailments unless the couplers are faulty, or there is interference between the rotating trucks and parts of the frame/body above them, or the rails are not even transversely across at any one point along the place where you are having derailments.
 
Ah yes, that's the other thing (Crandell just reminded me), sidesteps/stirrups on the cars. Some of my Walthers 85'ers won't go round even curves that are greater than the claimed minimum because of side stirrups that foul the ends of the trucks when they're swung out. One particular car, an ACF RPO has a pair of long ones that catch the truck so much, the truck actually gets hooked onto either one. A bit of a shelf queen, as I'm loath to cut off the offending stirrups, bending them out is not much of an option 'cause they're likely to break off.
 
P.S. I'm thinking of converting that RPO to a crew/tool/power car, then I can cut those stirrups off.
 
Thanks. We actually observed that the issue almost happens when the train runs across the 30degree crossing... although it only happens going in one direction, it almost certainly de rails on the same exact point... it seems that the leading truck will lift off the track... it also appears that there is a dip in between the rails so we have to replace the track and re test...

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Try turning the offending coach end for end if it's a particular one that's doing it, see if that makes any difference. If there is a dip across one intersection of the rails within the crossing, what could happen is if they're 4 wheel trucks, 3 will follow the level part, causing the 4th to ride up and out. If they have 6 wheel trucks (and this happens with 6 wheel locos too) then the truck may pivot about the center axle (more so on high spots
 
Thank you for the replies... it seems that the card are running better and less prone to derails now that we are investigating the tracks...

If we have a good flat track laid down, should we still encounter derailment in general? Sometime it seems that random cars will jump out of track at random places after several passes around the layout...

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Q. Are you running the passenger trains as a bloc, without doing any switching, uncoupling, etc.? If so, replace all couplers with Kaydee's. But the uncoupling pins off or at least bend them up enough so there is no chance of the uncoupling pin striking the ties, frogs, guard rails, etc.

Q. Are you lighting the interior of the cars using power picked up by metal wheels? If so, you might consider changing to battery-powered lighting, and change all wheel/axle sets to 36" diameter metal ones.

Consider adding weight to the inside of the cars. As previously suggested, check the tops of trucks AND couplers to see they are not rubbing on the underside of the cars, especially when the couplers swing back and forth. Leave about 1/8" or more gap between diaphragms on the ends of the cars. Yes, there will be a gap on the straight-aways, but the diaphragms on coupled cars won't tend to catch going into or coming out of the 18"R curves. If you have any 85' cars running with the 72' cars, intermix them so you don't have two 85' directly connected. Check the flangeways, and flangeway depths of that 30 deg. crossing. It may be there is something out of gage. Sometimes deepening the cuts with a needle file will help.
 
burakol said:
Thank you for the replies... it seems that the card are running better and less prone to derails now that we are investigating the tracks...

If we have a good flat track laid down, should we still encounter derailment in general? Sometime it seems that random cars will jump out of track at random places after several passes around the layout.
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No, if the track is all smooth, no kinks, dips, and is all in gauge the track should not be causing the derailments. Have you put a track gauge to every place there is a derailment?

If the track is all good I still say the next thing is to check the wheel gauges.

Then Also:
1. If they have plastic wheels check for chips or bumps on the wheel flanges.
2. Check the coupler action to be certain they move both directions and all spring back from both sides.
3. Check that no coupler is hanging too far down. The XR2 couplers have a small point on the bottom for uncoupling. Since the uncoupling on that type of coupler never works right anyway they can be trimmed up a bit. Sometimes they hang too low and can catch on cross rails (turnouts, crossings, etc.).
4. Check the trucks are pivoting properly and not bumping into anything.
5. Check the trucks are not on too tight such that they can rock a bit from side to side and front to back.

If all of that doesn't resolve the issues then I would try what trailrider said and add about and ounce of weight to each car.
 
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All good advice by Iron Horseman. The Athearn and other shorty passenger cars are manufactured to run on 18"R curves so it's not hopeless, it's a matter of identifying the problems and correcting them. Good luck.
 
My '85 car run on my 18r curves all that time without a problem... for the most part.
They hate some (not all) of my Atlas Switchtrack turnouts when going onto or coming off of the diverging rail. I had one that would constantly derail over one particular turn out. After a lot of investigating, the issue turned out to be the track work prior to the turnout that was causing the leading wheel on the leading truck to rise up a little bit and the flange would start riding on top of the rail. A slight curve followed and off it would come. once I fixed that, they've worked pretty well.
 
Thanks.. for the most part, they are now running better than it was initially... still not perfect especially when backing up... we had to replace the lead car's coupler to a kadee knuckle and kept the rest as is with the plastic horn hooks and that may be causing issues when backing up... our track work is definitely not perfect... i asked my students if they wanted to redo a new layout... a more simpler one...

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Reversing a train of model passenger cars is pretty much always fraught with difficulty, especially through turnouts and curves. The couplers are designed mainly for pulling, they will assume some odd angles under compression loads. Without checking back, I'm assuming you're using sectional track rather than flex that can be cut to custom lengths. Sectional doesn't always line up exactly as required when not following a preset, accurately designed plan, inviting some forcing of joints to make it fit and creating kinks and misalignments. The death knell of smooth operation. Your students are learning that not all ideas are practical. Valuable lessons that apply in all facets of life, not just model RR'ding.
 
Just checked back to your main layout thread (Hint here, sometimes it's better to keep all posts about a project in the same thread, even though the subject matter may seem different) and I see that you are using sectional track. There is no reason that where you find misalignment problems with that, that you cannot use a piece of Flextrack to overcome that particularly if it's the same brand of track. If you do try this, it's best to replace a couple of the settrack pieces, rather than try to fix a kink with just a short filler piece to get a better alignment. Your current layout has a lot of appeal, may make it harder to scenic, especially tunnels where you need access from the back in case of derailments within. Your students obviously are having a lot of fun, as no doubt you are too.
 
Yeah, its a lot of fun when trains do run... but as with kids nowadays, problem solving skills are quite a challenge that they are continually trying to develop... in the end, most work is left for me...

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burakol said:
Yeah, its a lot of fun when trains do run... but as with kids nowadays, problem solving skills are quite a challenge that they are continually trying to develop... in the end, most work is left for me...

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It's a bit like taking your car to a mechanic these days, if the fault doesn't show on a computer screen, they have no idea how to find or fix it. God help the world when all us 'practical' people are gone. Consider yourself one who is trying to prolong that evil day. :rolleyes:
 
And to follow up on Tootnkumin's comment, and to go back to one of your initial questions, Yes, replace the couplers with knuckle couplers. Backing it up will work 1000 times better than with horn hooks.

At least, that has been my experience.
 
We have to purchase the couplers.... this is what I did for the first car that connects to he engine... I converted it to a knuckle and kept the other cars as is with the hook couplers... i had to 3d print longer box to extend the coupler further out...

When buying the kadee coupler, is is safe to assume that getting the whisker design is better than the older one??? If we are to convert it to all knuckle, do we still need to have it attached to the truck, or move it to the body?
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